Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The present invention relates to a pyrometallurgical
furnace installation, more particularly for smelting ore
concentrate and after treating the melt, with furnace walls in
which at least the area coming into contact with the melt and~or
slag comprises individual cooling elements through which a
coolant flows.
In one known pyrometallurgical furnace installation,
for example for smelting finely granular sulphidic lead ore
concentrate (German OS 29 35 394, Figures 4 and 5), the furnace
walls comprise, in the area which comes into contact with the
molten slag, of individual cooling boxes made, for example, of
copper and containing duc s through which the cooling water
flows. The pronounced cooling effect causes a thin layer of
slag to freeze onto the surfaces of the cooling boxes, thus
protecting them from attack by the hot aggressive slab bath.
Because of their size, the cooling boxes, which extend over the
entire height of the slag bath, are relatively heavy and cumber-
some. Individual cooling boxes can be replaced only when the
furnace is cold since, when the furnace is hot, outwardly braced,
immediately adjacent cooling boxes are locked in position by
thermal expansion, even if the faces of the joints were to be
tapered. Such tapering would still allow only every second
cooling box to be removed without previously removing the
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relevant adjacent box.
It is an aim of the present invention to provide a
furnace-installation having furnace walls, the cooling boxes
- or cooling elements of which, in contact with the molten slag,
are easy to install and remove, the said cooling elements being
individually replaceable, as soon as the slag has been tapped
off and while the furnace is still hot, whenever repairs are
required (which means that the furnace is down only during a
short time), and also having other advantages.
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~ ccording to the invention, the aim is achieved
by providing a pyrometallurgical furnace installation, more
particularly for smelting ore concentrate and after treating
the melt, with furnace walls in which at least the area comin~
into contact with the melt and/or slag comprises individual
cooling elements through which the coolant flows, characterized
in that adjacent cooling elements (15 to 18, 59, 60) are
respectively secured detachably to a common cooling element
- carrier (22, 61), supported towards the outside by a stationary
support structure (29), by means of support elements (49, 41),
and which comprises at least one hinge (25, 26, 62, 63) per
cooling element carrier, by means of which each carrier can be
pivoted outwardly, after the manner of a door, out of the furnace
wall. Further advantageous configurations are discussed herein-
after.
In the furnace installation according to the present
invention, the cooling boxes which come into contact with the
~ slat comprise plate-like cooling elements, preferably made of
copper, arranged horizontally one above the other and provided
with coolant ducts, a plurality of such superimposed elements
being secured detachably to a common cooling element carrier,
! designed after the manner of a door and preferably made of sheet-
steel. These door-like cooling element carriers, adapted to be
swung outwardly out of the furnace wall upon hinges, are in
turn supported outwardly by a stationary support structure.
The said cooling elements, being relatively light in
weight, are easily handled during installation and removal.
When repairs are needed, the slag in the furnace is tapped off,
the support elements between the door-like cooling element
- 30 carriers and the stationary support structure are removed, where-
;~ upon the relevant cooling element carriers may be swung out of
the furnace-wall, while the furnace is still hot. The individual
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cooling element~ qecured to the carrier detachably, for
example by a sliding connection, may then be easily and quickly
replaced or even interchanged, since the individual cooling
elements are of the same size. Thus furnace downtime for the
repair of the water cooled cooling elements is reduced to a
minimum. In the design according to the invention, there is
clear distinction between the cooling function exercised by
the cooling elements and the carrying function exercised by the
carrier elements and support elements. The plate-like cooling
elements, with their coolant connecting lines, project outwardly
from the furnace wall between the horizontal, adjacent, door-
like cooling element carriers. The sliding seat joint between
the door-like cooling element carriers and the individual plate-
like cooling elements secured thereto allows the said elements
to move freely during thermal expansion, and the door-like
cooling element carriers, supported by the stationary support
structure, can also take part in such thermal expansion. All
in all, the design according to the invention is characterized
by a high ratio between the effective furnace wall cooling area
and the weight of the cooling elements. At the same time, rapid
access to the interior of the f~rnace is available.
The invention and further characteristics and
advantages thereof are explained hereinafter in greater detail,
;- in conjunction with the examples of embodiment illustrated
~ diagrammatically in the drawing attached hereto, wherein:
;~ FIGURE 1 is a vertical section through the pyro-
metallurgical furnace according to the
invention, along the line I - I in
Figure 2:
FIGURE 2 is a horizontal section through the
furnace-installation along the line II - II
in Figure 1:
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FIGURE 3 is an enlarged view of detail III in
Figure 2;
FIGURE 4 is a view in the direction of arrow
IV - IV in Figure 2,
FIGURE 5 is a modification of the vertical
section in Figure 1, along the line V - V
in Figure 6,
FIGURE 6 is a cross-section along the line VI - VI
in Figure 5.
The pyrometallurgical furnace installation
illustrated in the figures may be used, for example, for smelting
finely granular, suphidic lead ore concentrate. Molten lead 11,
the surface of which is marked 12, collects in a crucible 10
resting upon a foundation. Located above surface 12 is a slag
bath 13, the surface of which is marked 14. The part of the
furnace wall which comes into contact with slag 13 is protected
by individual plate-like cooling elements 15, 16, 17, 18, pre-
ferably made of copper, arranged one above the other, and
traversed by a flow of cooling water. As a result of the
pronounced cooling action, a thin layer of slag freezes onto
the surfaces of cooling elements 15 to 18, which are thus
protected from attack by the slag bath.
As shown clearly in Figure 1, retaining elements 19
project from the backs of cooling elements 15 to 18, by means of
which the said cooling elements are inserted into horizontal
rails 21. The latter project from the front face of a cooling
element carrier 22 consisting of an outwardly open sheet steel
housing. Arranged on arms 23, 24 on cooling element carrier 22
are upper and lower hinges 25, 26, the said hinges being secured
to a vertical beam 29 by means of ~pport elements or links 27,
28. In order to relieve the load on the said hinges and links,
the bottom of cooling element carrier 22 rests upon crucible 10
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when the said carrier is in the operative position~
According to the example of embodiment illustrated
in Figure 1, four plate-like cooling elements 15 to 18,
arranged horizontally one above the other, are secured detachably
to a common coolins~ element carrier 22. Figure 2 shows three
such horizontally adjacent cooling element carriers 22, 30, 31,
each of which carries four platelike cooling elements. Just as
c arrier 22 has ~ts hinge 26, so does carrier 30 have its hinge
32 and carrier 31 hinge 33, the said hinge elements allowing
10 each cooling element carrier to swing outwardly, after the manner
of a door, in the direction of arrow 34, out of the furnace wall.
In Figure 2, upper cooling element 35 on carrier 31, through
which element cooling water flows, is being pulled out for
replacement in the direction of arrow 36, while lower cooling
element 37 is still in its inserted or pushed in operative
position.
As also shown in Figure 2, the stationary support
structure has vertical beams 29, 38, 39, 40 arranged 2,40 m
apart, a distance which corresponds to the spaces between
hinges 26, 32, 32 of adjacent cooling element carriers 22, 30,
31 and thus approximately to the horizontal length thereof.
; Vertical beams 29, 38, 39 are joined together by horizontal beams
41, 42. Wedges or keys 47 to 50 are adapted to be inserted
between the said horizontal beams and inner stiffening ribs 43
to 46 of cooling element carriers 22, 30, so that the said cooling
element carriers, which are adapted to swing after the manner of
doors, are firmly supported. Whereas the length of each plate-
like cooling element amounts to about 2,40 m, the height of all
four horizontally superimposed cooling elements amounts to about
1,30 m. The centres of rotation of the individual cooling element
carriers are preferably located :Ln the vicinity of one end thereof.
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According to Figures 2 and 3, a gap is provided
between horizontally adjacent cooling element carriers, 30, 22,
. through which cooling elements 51, with their longitudinal ends
52 bend outwardly on one side, and the feed and return lines
53, 54 are carried outwardly from the interior of the furnace,
the said adjacent cooling element carriers being connected to
each other, in the vicinity of the said gap, by a tensioning
` means 55, for example a threaded bolt. According to Figure 3,
the said gap is also sealed by strips 56 of sealing material,
for example asbestos which, when the furnace installation is
i being started up, ensures gas-tight sealing of the interior of
~ the furnace. According to Figure 1, each of the plate-liXe
t cooling elements, preferably made of copper, comprises a cool-
ant feed duct 56 and a coolant return duct 57 connected thereto
and located thereabove. It may be seen from Figure 4 that,
of the four horizontally superimposed cooling elements 51, 51a,
i 51b, 51c, the lowermost element 51c is connected to a coolant
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feed line 58 while the uppermost element is connected to a
;- coolant return line 54, the coolant ducts of adjacent cooling
20 elements being connected together through U-shaped elbows 53.
In the example of embodiment according to Figure 5,
cooling elements 59, 60, preferably made of copper, are of
angular configuration, as seen in vertical section and engage
around the upper and lower edges of cooling element carriers
61 comprising hinges 62, 63.
In this design, the transition between the furnace
wall area of lowermost cooling element 60 and crucible 10 is
very well protected since, because of the large cooling contact
area, a protective layer of solidified slag is formed, when the
: 30 furnace is in operation, on the inner wall thereof and in any
fissures therein. In Figure 6, the same purpose is served by
the overlap 64, 65 in the vicinity of the gap between adjacent
cooling element carriers 67, 61.
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Thermal expansion in the wall of the furnace i9
absorbed by the sliding seat between the cooling elements and
their carriers and, according to Figure 2, also by hori-
zontally displaceable mounting 68 of links 69 carrying hinge
33 of relevant cooling element carrier 31.
Should one or more cooling elements require repair,
slag 13 is tapped from the furnace installation. As shown
in Figure 2, tensioning device 55, or the like, is then
released. After wedges 49, 50 horizontal beams 43, and
the corresponding parts of adjacent locations have been
removed, and the coolant feed and return hoses haVe been
~ disconnected, the relevant cooling element carrier, as
; demonstrated by cooling element carrier 31 in Figure 2 can
be quite easily swung out of the furnace wall in the direction
of arrow 34, while the furnace is still hot. Damaged
cooling element 35 is then easily withdrawn and replaced by
a new cooling element, thus allowing the old element to be
repaired at leisure. In order to close the furnace and set
it in operation again, the sequence of operations is reversed.
Furnace downtime for repairs to cooling elements is thus
reduced to a minimum.
